|
. First Quarter 2004
<br /> Thrifty#171
<br /> April 21,2004
<br /> Page 2
<br /> A summary of historical analytical sampling results for TPHg, BTEX, and MTBE is provided in
<br /> Table 1, and oxygenate/alcohol results are summarized in Table 2 Copies of the EMC Field
<br /> Status Reports are presented in Appendix A, and copies of the laboratory analytical reports are
<br /> contained in Appendix B
<br /> TPHg, benzene, and MTBE isoconcentratron maps are presented as Figures 2, 3, and 4,
<br /> respectively The analytical laboratory results indicate that the highest groundwater
<br /> concentrations of TPHg, benzene, and MTBE were found in monitoring well MW-5 (38,900
<br /> ug/L, 2,850 ug/L, and 10,000 ug/L, respectively) The selected oxygenate concentrations were
<br /> below laboratory detection limits, however, the method detection limits were elevated for DIPE,
<br /> ETBE, TAME, and TBA in well MW-5
<br /> The laboratory inadvertently did not run ethanol and methanol even though they were requested
<br /> on the chain-of-custody The results for ethanol and methanol will be reported to the San
<br /> Joaquin County Environmental Health Department (SJCEHD) under separate cover as soon as
<br /> they are available
<br /> Remediation Status
<br /> On July 1, 1999, a Baker Furnace Thermal Oxidizer Unit was placed into operation, to destroy
<br /> vapors extracted by the SVE system Presently, the remediation system is connected to SVE
<br /> wells MW-2, MW-4, MW-5, TB-3, TB-4, TB-6, TB-7, TB-9 (A, B), TB-11 (A, B), and TB-12
<br /> (A, B) A map presenting the extraction well layout is shown as Figure 5 The only wells
<br /> operating this quarter were TB-11 wtr(50%), MW-5 (100%), and TB-3 (50%)
<br /> During this reporting period, the soil vapor extraction unit operated approximately 1,833 hours
<br /> and approximately 3,445 pounds of hydrocarbon as TPHg were removed this quarter as of March
<br /> 30, 2004 (Table 3) The cumulative system total as of March 30, 2004, was approximately
<br /> 28,473 hours of operation and approximately 137,632 pounds of hydrocarbon as TPHg removed
<br /> The system operated throughout the quarter except when it was shut down for quarterly water
<br /> sampling from February 9 though February 16, 2004 The system was also found to be down on
<br /> February 2, February 23, March 1, and March 22, 2004, due to mechanical problems In each
<br /> case, the system was restarted the same day Field records of the SVE system are provided in
<br /> Appendix C
<br /> Vapor samples were collected from the system inlet and outlet ports on January 12, March 23,
<br /> and March 15, 2004 Vapor samples from selected wells were collected on February 23, 2004
<br /> The samples were analyzed for TPHg by EPA Method 8015M for gasoline, BTEX, and MTBE
<br /> by EPA Method 8021 B
<br />
|